The present invention relates to a method and apparatus for determining the position and dimensions of a test object by means of a measuring system coupled to a switching sensor, wherein the switching sensor is movable relative to the test object with an approach velocity, wherein the measuring instrument generates a measuring signal indicative of the relative position of the switching sensor with respect to the test object, and wherein the switching sensor generates a sensing signal upon contact with the test object.
European Patent Application No. 0 029 499 discloses an arrangement for determining the dimensions of a test object by means of a switching sensor movable relative to the test object. A measuring arrangement is included for measuring the relative position between the test object and the switching sensor. At the moment of contact between the switching sensor and the test object, the switching sensor generates a sensor signal which causes the instantaneously prevailing measuring value of the measuring instrument to be stored.
Typically, during operation the switching sensor approaches the test object with an approach velocity that can vary widely. It has been shown that in systems of the type described above the measured position of the test object is affected by errors caused by deformation of the switching sensor and of the test object at the common contact point between them. Such deformations vary in the first place as a function of the sensing speed or velocity of approach between the switching sensor and the test object and, in the second place, as a function of the materials used for the switching sensor and test object.